The relationship between anthropometric factors and body-balancing movements in postural balance

Objective: To evaluate the relationship between anthropometric characteristics and body-balancing movements when standing on 2 legs with eves open and eyes closed. Design: Cross-section A Setting: A university physiatry laboratory. Participants: One hundred randomly selected subjects (50 men, 50 women; age range, 31-80y). Interventions: Not applicable. Main Outcome Measures: Anthropomorphic: body height. weight, lower-extremity distances, foot lengths, and widest widths of the forefeet and heels. Body movements: 2-legged stance with eyes open and eyes closed. measured with the MacReflex Motion Capture System and calculated as maximal and total movements in 3 dimensions. The relation between the measured anthropometric characteristics and body-balancing movements was calculated by using regression analysis. Results: In the eyes-open condition. maximal lateral knee movement was related to body height and foot length (R-2=.065, P<.05). Both anteroposterior (AP) head movement (R-2=.068, P<.05) and AP navel movement (R-2=.083, P<.05) were related to heel width. AP Knee movement was related to foot length and heel width (R-2=.089, P<.05). Body mass index was related to AP ankle movement (R-2=.074. P<.05) and to vertical ankle movement (R-2=.063, P<.05). In the eyes-closed condition, body mass index was related to the vertical navel movement (R-2=.059, P<.05) and body height to AP knee movement (R-2=.041, P<.05). Conclusion: The levels of significance are not high but warrant attention. It seems that there was no single anthropometric factor that explained the variations in body-balancing movements during standing.